New Jersey Gov. Chris Christie refused to rule out a 2016 presidential run Tuesday night during the first debate in his gubernatorial re-election campaign.

The Republican governor said he could "walk and chew gum at the same time," balancing the demands of a second term and his political future.

"I am not going to declare tonight ... that I am or I'm not running for president," Christie said and later added, "I won't make those decisions until I have to."

The comments underscored the broader stakes for the outspoken governor during an event that could be a tuneup for a prospective presidential campaign. Should he run, Christie would begin campaigning in the midst of his second term as governor.

In the first three years of his first term, Christie's national profile has grown substantially — he was the straight-talking face of the state's response to Sandy and has sought high-profile roles including keynote speaker at last year's Republican National Convention.

His debate opponent, Democratic state Sen. Barbara Buono, has been given little chance at unseating the popular governor. The only unsettled question appears to be Christie's margin of victory in this Democratic-leaning state.

Buono, 60, who has struggled to stay on-message and has been outraised by more than 4-to-1, attacked Christie as a nationally ambitious politician whose every calculation is based on his national aspirations.

"It doesn't bother me that you're running for president. What bothers me is how you're running for president," Buono said.

Christie, 51, who is sometimes accused of bullying his opponents, did not apologize for his sometimes-harsh language.

"Using direct and blunt language is something I've done my whole life. It's the way my mother raised me," Christie said. "I am who I am. And I'm not going to change. I think they're comfortable with the leadership I've provided over the last four years in this state."

He also touted his ability to reach consensus with New Jersey's Democrat-led Legislature, and will contrast his signature bipartisan achievements of ending lifetime teacher tenure and winning benefits concessions from public-sector unions with the gridlock in Washington that has led to a government shutdown.

Buono countered that Christie's stance on other issues — his opposition to gun control legislation, his decision to block funding for women's health care, and his move to veto legislation that would have legalized same-sex marriage in New Jersey — were tailor-made for GOP primary voters.

Christie said he believes marriage should be between one man and one woman, but suggested that the issue should be decided by a statewide referendum.

"If they do decide to change the definition of marriage by referendum, then I'll support that law and enforce that part of the constitution with the same vigor that I've done over the last four years with every other part," he said.

Christie portrayed his opponent as a tax-and-spend liberal, much like former Gov. Jon Corzine, who Christie unseated four years ago.

The message wasn't new, but viewers saw a thinner version of the governor. Christie said last month he's more than halfway to the dieting goal he set after undergoing weight-loss surgery in February. Having faced continued questions about his health, Christie said during the debate that he would release his personal medical records.

Buono, a 20-year state legislator, is giving up her state Senate seat to run against Christie. When asked for an attribute they admire in each other, Christie complimented his opponent as "a good and caring mother and someone who cares deeply about public service in the state."

Buono said of Christie, "he's good on late-night TV, he's just not so good in New Jersey."

The two meet again next Tuesday for the second and final debate required under state election law for candidates who are accepting public financing.